//公共flex布局
.common-flex(@justify:space-between,@align:center,@flow:row) {
  display: flex;
  align-items: @align;
  justify-content: @justify;
  flex-flow: @flow;
}

//定位上下左右居中
.fxied-center() {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}
